The invention relates to a full flow auxiliary oil system for an air-cooled engine, and more particularly to an oil pump cover which adapts a Volkswagen type engine for a full flow auxiliary oil cooler or filter.
Air-cooled engines are typically provided with oil filters and coolers because the integrity and temperature of the oil is an important factor in determining the temperature of the engine and an important factor in engine life and performance. For example, early Volkswagen type engines were provided with an oil cooler which was located within an air cooling fan shroud of the engine. The air within the fan shroud would circulate around the oil cooler and thereby also cool the engine oil as well as circulate air over the cylinders. With the advent of off-road vehicles and higher performance demands on the engine, it has become advantageous to add auxiliary oil filtering capabilities and larger oil cooling capacity far beyond that provided by the standard engine. The engine compartments of such vehicles are usually quite confined and also very hot. It is therefore advantageous to locate the auxiliary oil system remotely from the engine compartment, typically on the exterior side or roof of the vehicle, where it is exposed to cooler exterior air flow.
The prior art has provided numerous engine modifications and adapters to convert the standard Volkswagen type engine to that of a full flow system for the remote location of an auxiliary filter or cooler.
One method of providing such a full flow auxiliary system involved the drilling into the engine block through an oil high-pressure passage, then tapping threads for an oil hose fitting. Then similarly, drilling, tapping and installing a hose fitting for the return of the oil to the engine. An auxiliary oil cooler, for example, was then installed remotely from the engine compartment and interconnected by oil hoses to the respective fittings on the engine. This process involved substantial time and skill in removing and reinstalling the engine as well as the precision installation of the oil fittings, and represented a substantial expense to the owner of the vehicle.
Another early approach, by the present inventor, is shown in U.S. Pat. No. 4,424,778 in which a coupler was installed at the standard oil cooler location which provides for the installation of an auxiliary oil cooler. The use of the coupler required that the engine shroud be removed, the oil cooler be removed, the coupler then be installed, then the standard oil cooler reattached at the coupler, then the auxiliary oil cooler and lines be attached to the coupler at the rear of the engine, the shroud was modified for clearance of the new lines and cooler, then the shroud was reinstalled on the engine. This device required substantial time, skill and expense for the installation.
Additional adapters are available which are attached at the oil cooler location which replace the oil cooler with a device which provides an outlet and inlet for a full flow auxiliary oil system. A disadvantage of these adapters is that the remote cooler performs properly so long as the vehicle is moving, but when stationary, such as in heavy traffic, the cooling of the replacement coolers are not exposed to the air flow within the shroud and the oil cooling is often inadequate under such conditions. In addition, these devices also require removal of the engine shroud; the oil cooler, installation of the device, and reinstallation of the shroud, all at substantial time, effort and expense to the owner.